Back ground: Osteoarthritis is the most common joint disease and a major cause of disability worldwide. It severely impairs patients' ability to carry out activities of daily livings including basic tasks  .The aim of this study was to assess patients' knowledge and practices toward osteoarthritis disease . Research design: A descriptive analytical study was utilized. Setting: This study was conducted at orthopedic outpatients' clinics at El Nil hospital for health insurance in shubra elkheima city. Sample: A purposive sample of 77 patients with osteoarthritis was chosen according inclusion criteria. Tools: Two tools were used first tool: Interviewing questionnaire for patients was used, including three parts: part (I) Socio-demographic characteristics about patients. Part (II)present history about patients, part (III)Patients' knowledge assessment level related to osteoarthritis disease. Second tool: Patients' practices assessment level related to osteoarthritis disease as reported by them .Results: most of patients had unsatisfactory level of knowledge regarding osteoarthritis disease. Most of patients had satisfactory level of practice related to correct postures. More than two thirds of patients had satisfactory level of practice related to activities of daily living (ADLs). Conclusion: The study concluded that a positive correlation between patients' knowledge and their practices related to osteoarthritis disease. Recommendations: Increasing awareness of patients about osteoarthritis disease through mass media and social networks. Conducting in service training and educational programs periodically and regularly to improve patients' knowledge and practices related to osteoarthritis disease.